Computing systems often require operations to be carried out in a secure manner. For embedded computing devices and for pervasive systems, security of operation is often crucial. To ensure operations and communications are secure, such systems employ cryptographic methods.
The implementation of such a cryptographic method must itself be secure. However, cryptographic methods are subject to attacks. One type of non-invasive attack on computing devices implementing cryptographic methods is known as a side-channel attack. A side channel attack is any attack on the computing device based on information gained from the physical implementation of the computing system, rather than using a brute force attack or exploiting a theoretical weakness in the cryptographic algorithms. For example, timing information, power consumption, electromagnetic leaks, and sound can be used to as sources of information that can be used to break a system.
A power consumption attack, for example, involves the monitoring of the power consumption of one or more components of a device while the device executes a cryptographic method. One example of a power consumption attack is a differential power analysis. The data derived from monitoring power consumption of the device, combined with some knowledge of the operations being carried out by the device, can be used to derive the secret information that is part of the cryptographic method. It is therefore desirable to provide a mechanism for disguising a power profile of a computing device executing secure code in order to prevent a side-channel attack that uses power consumption information.
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